Effect of Post-metallization Annealing for Alternative Gate Stack Devices

The effect of the post-metallization annealing of devices having or dielectrics and poly-Si or TaN gate electrodes was studied. Forming gas (10% annealing at 400°C enhanced drive current and channel mobility of devices having 1.2 nm gate dielectrics, by eliminating interface states. Post-metal annealing in 10% for 1.2 nm gate dielectrics resulted in larger enhancements in drive current and device channel mobility than forming gas annealing. Similar enhancements of the device characteristics were observed in (300 mV shift in both flatband and threshold voltage) and (200 mV shift only in threshold voltage) materials. Annealing in pure nitrogen was found to degrade the dielectric quality of including a decrease in device current and 50% lower capacitance.